The present invention relates to a pump sprayer assembly for the spraying of liquids or fluids. More particularly, the present invention relates to a pump sprayer for spraying fluids which contain a solid particulate matter or powder in solution or suspension therein.
Pump sprayers are typically used for dispensing fluids such as cleaning fluids, insecticides, fertilizers and various other liquids. Conventional pump sprayers include a supply tank or reservoir dimensioned to hold a predetermined volume of liquid, a manual pump or piston, a pressure vessel or accumulator, a discharge valve, and a spray wand with a nozzle from which the fluid is discharged. In some conventional pump sprayers, the reservoir or supply tank performs its intended function and also serves the function of the accumulator or pressure vessel. In operation, the reservoir initially contains air at atmospheric pressure and the fluid to be sprayed. The operation of the pump forces air into the reservoir, thereby increasing the pressure of the air therein. The compressed air, in turn, exerts pressure on the fluid contained in the reservoir. Operation of the discharge valve allows the pressure within the accumulator to push the fluid out through the nozzle until the valve is closed or equilibrium is reached.
Conventional pump sprayers are not adapted for the spraying of fluid containing solid particulate matter suspended therein. Particulate matter which is suspended in a fluid tends after a period of time to settle out of suspension from within the fluid. Conventional sprayers generally fail to provide a means for maintaining the particulate matter in solution or suspension. Therefore, such a fluid applied from a conventional sprayer is likely to contain an amount of the particulate matter that is not optimal.
The particulate matter typically settles at or near the bottom of the reservoir of the sprayer. Conventional sprayers generally intake the fluid to be discharged from a location which is at or near the bottom of the reservoir. Thus, intake occurs at or near the area in which settled particulate has accumulated. This results in the intake by the sprayer of fluid having an increased concentration of solid particulate matter. This increased concentration of particulate may be significantly higher than the intended or recommended concentration. In use, such an increased concentration of particulate near the intake may result in over application. The potential exists for the application of excessive, perhaps even dangerous, concentrations of the active ingredient in the applied fluid, such as pesticide or fertilizer, and may result in damage or injury to property, plants, animals, or perhaps the user of the pump sprayer. After the portion of the fluid that contains a higher concentration of particulate due to settling is discharged, the situation reverses and the opposite problem occurs. The remaining fluid will have a lower than intended concentration of particulate. The concentration may be low enough to render the particular fluid ineffective for its intended use.
Furthermore, conventional sprayers tend to become clogged by the particulate matter suspended within the fluid. As referred to above, the particulate matter tends to settle out of solution with the fluid and accumulate near the bottom of the reservoir proximate the intake. The settled particulate matter results in a reduced volume of fluid in the region surrounding the intake and, therefore in a reduced volume of fluid being dispensed from the sprayer at a given pressure. Over time, this high concentration of settled particulate may clog the intake itself, the spray nozzle, or any various other points along the discharge path. Such clogging requires a user to dismantle the sprayer and remove any clogs by manually cleaning the sprayer. This process is time consuming and can be, depending on the particular sprayer, of moderate complexity. Furthermore, the process of clearing a clog may expose the user to hazardous chemicals.
Adding a filter to the intake of a conventional sprayer will not completely alleviate the problem of reduced fluid flow or of clogging. As settling of the particulate matter occurs, the particulate matter accumulates on and around a filter. Other particles and foreign substances having a particulate size larger than the filter passages also accumulate on and around the filter. The settled and foreign accumulated particulate matter displaces the fluid from the region surrounding the filter and, therefore, restricts the volume of fluid being discharged from the sprayer. A clog results when the pressure within the reservoir is insufficient to impart enough energy to enable the fluid to displace or flow through the accumulated particulate matter. Furthermore, simply increasing the pressure upon the fluid tends to exacerbate the clog. Under increased pressure, the fluid simply pushes the accumulated particles more strongly against a filter. When the concentration of accumulated particulate matter reaches a certain point, increased pressure alone will not provide the fluid with enough energy to flow through or displace the particles. Thus, a conventional sprayer having a filtered intake that is being used to dispense fluid having particulate matter suspended therein may still clog. The timely, complex, and potentially hazardous process of disassembly being required in order to remove the clog.
What is needed in the art is a sprayer assembly for the spray application of a fluid containing solid particulate matter suspended therein which will: prevent the settling of the particulate matter out of solution with the fluid; return settled particulate matter into suspension with the fluid; provide improved resistance against clogging; and provide a way to dislodge particulate matter that has accumulated on and around the sprayer intake.
The present invention provides a sprayer assembly for sprayingly dispensing a fluid having particulate matter in suspension therein.
The invention comprises, in one form thereof, a sprayer assembly including a reservoir. The fluid to be sprayed is contained in the interior of the reservoir. The reservoir includes a first opening for receiving the fluid and a second opening for dispensing the fluid. A pump is received in the first opening and includes a pump handle disposed exterior to the reservoir and a pump mechanism disposed in the reservoir interior. The pump is operable to increase the pressure in the reservoir interior. A discharge tube has an outlet end fluidly connected to the reservoir second opening and an intake end disposed in the reservoir interior. A filter having a plurality of filter passages is disposed within the reservoir interior and is associated with the intake end of the discharge tube. The filter prevents particles larger than the particulate size from passing into the discharge tube. An agitator is disposed in the reservoir interior and creates a fluid turbulence around the filter and thereby dislodges accumulated particles from around the filter and from the filter itself.
An advantage of the present invention is that the filter allows fluid to enter from all sides and therefore provides improved resistance against particulate matter clogging the filter.
Another advantage of the present invention is that the agitator creates a turbulence in the liquid contained in the reservoir of the sprayer thereby maintaining particulate matter in suspension with the liquid. Thus, proper concentration of particulate matter in the fluid being discharged from the sprayer is maintained.
Yet another advantage of the present invention is that the turbulence in the liquid occurs in a region surrounding the filter. The turbulence dislodges settled particulate matter from that region and from the filter itself. Thus, it is ensured that a full volume of fluid is dispensed at a given pressure and clogs are prevented.